This invention relates to laser-fusion targets, particularly to foam-encapsulated laser-fusion targets, and more particularly to an encapsulation method for producing fusion fuel-containing capsules in small cell size, low density foam.
Formation of low density foams and encapsulation of microspheres and fillers therein are known in the art, as exemplified by U.S. Pat. No. 3,849,350 issued Nov. 19, 1974.
Conventionally known foams, such as polystyrene, polyurethane, polyethylene, etc., can be obtained in low densities between 0.01 and 0.1.times.10.sup.3 kg/m.sup.3. However, the cell size is generally too large, 25 to 200 .mu.m and above, to meet the requirement for foam-encapsulated laser targets which require a foam having both low density and very small cell size, preferably less than 1-2 .mu.m. Thus, a need exists in the prior art for a low density, very small cell size foam and method of encapsulating fusion fuel therein.